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Eczema (Dermatitis) is a condition that appear as a skin inflammation. 

There are different types of eczemas and the underlying reasons for them vary. 

The cause of eczema may be:


Inherited and chronic by nature

Triggered by irritant substances**  or 

Triggered by allergic reactions.


Eczemas triggered by allergic reactions, Allergic Contact Dermatitis (ACD), appear on the skin of people who have developed a Contact Allergy.


Contact Allergies are not inherited but are developed over time by exposing the skin to certain substances. Substances causing Contact Allergy are called Haptens. Once Contact Allergy has been developed, the skin will inflame when in contact with the hapten that caused the allergy.



 Common Haptens

Common causes for Contact Allergies are substances found in cosmetics, perfumes and in jewelry. These include:



Nickel and Cobalt are two well known haptens



 Preservatives found in cosmetics and shampoos such as Methylisothiazolinone, Formaldehyde and Quaternium 15



Many fragrances used in perfumes and scented products are allergenic, including substances such as Linalool, Limonene, Lyral and Myroxylon Pereirae Resin​




To find out if your eczema is caused by Contact Allergy you need to perform a Patch Test. Patch Tests are generally performed by dermatologists or allergists at skin clinics, to which you are referred to by your local GP.


Patch Testing


With over 500 haptens to choose from, the first step for an investigating physician is to narrow down the search criteria and identify which haptens that could be the probable cause of your eczema. This is done by gathering information on your daily routines, hapten exposure and work activities.



Patch Testing itself is a provocation test where the different haptens are applied into Patch Test Units which are taped onto your skin. In people with Contact Allergy, the Patch Test will result in miniature allergic reactions. The immunological reaction develops over 2-4 days, which requires you, the patient, to return to the clinic for interpretation of the result.


Have you been diagnosed with Contact Allergy?


Learn more about the hapten causing your eczema by searching our data base the search field at the top of this page, or by following this link and clicking the "HI" symbol next to the hapten.




Q: How is Allergic Contact Dermatitis treated?

A: There is no cure for Contact Allergy. Topical steroid creams and ointments may reduce the itchiness of the rash caused by contact allergies, but the only way to stay clear of Allergic Contact Dermatitis is to altogether avoid the hapten that is causing the eczema.  


Q: How do I look for haptens in products?

A: Make a habit of always reading the list of ingredients of products that you are using. Memorize the chemical name as well as possible trade names of the hapten that you are looking for. Possible synonyms for each haptens are available in our database.

Remember that terms such as "unscented" and "hypoallergenic" are unregulated and are not equal to "fragrance free" and "will not cause allergies".


Q: A previous Allergy Test showed no allergic reaction, could I still have Contact Allergy? 

A: Yes. Although the name suggests otherwise, Allergy Testing (Prick Testing / Intradermal Allergy Testing), does not test for skin allergies (contact allergies) but for food and respiratory allergies. Contact allergies can only be diagnosed by Patch Testing.


Q: Will my Patch Test results show if I am allergic to pollen, foods and pets?

A: No. As Patch Tests do not work in the same way as Allergy testing (Prick Testing / Intradermal Allergy Testing) a Patch Test can not test for respiratory allergies.


Q: Is my skin condition Allergic Contact Dermatitis?

A: A possibility of Allergic Contact Dermatitis (either as a sole skin problem, or complicating another skin disease) should be considered if:

  • Your dermatitis/eczema always (or frequently) becomes aggravated after a skin contact to particular objects (e.g. a pen, toy, shoes) or substances (e.g. hand cream, perfume, metal working fluid at your work etc.)
  • Your dermatitis/eczema is restricted to, or more pronounced in the areas of the body that were in most contact with the given object or substance.
  • Your dermatitis/eczema clears or improves during holidays, and relapses after returning back to your home or work.
  • Your dermatitis/eczema is mainly located on the hands, around the eyes, or in the genital area.
  • Your dermatitis/eczema lasts longer than 3 months, even if another diagnosis has already been established (other chronic inflammatory diseases of the skin may enable the penetration of sensitizers and promote sensitization).

Are you a physician looking for Patient Instructions?


Download our Patient Instruction Sheet to prepare your patients for a Patch Test screening. The Patient Instructions are available as a printable .pdf in English here.


* Atopic Dermatitis

** Irritant Contact Dermatitis

Are you a physician looking for Patient Instructions?

Download our Patient Instruction Sheet to prepare your patients for a Patch Test screening. The Patient Instructions are available as a printable .pdf in English here.


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